Anchor device

ABSTRACT

A drive-in anchor device for association with preformed holes in a support surface and which includes a plurality of spaced, sharp crested annular rings along the shank of the device. The plurality of rings including alternating large and small diameter rings.

United States Patent 1 1 [11] 3,867,864

Knohl Feb. 25, 1975 ANCHOR DEVICE 2,759,389 8/1956 Corckran 85/2! 85 75 inventor: Friedrich Karl Knohl, 12056116. 111. H9792 2/1935 Rmmberg 21 [73] Assignee: Illinois Tool Works, Inc., Chicago, FOREIGN PATENTS OR APPLICATIONS m 73,010 8/1916 Switzerland 85/2l [22] Filed: 3 Primary Examiner-Marion Parsons, Jr.

[21] Appl. No: 405,207 Attorney, Agent, or FirmRobert W. Beart; Thomas W. Buckman [52] U.S. Cl. 85/21 [51] Int. Cl. Fl6b 15/06 [57] ABSTRACT [58] Field of Search "fO53//2209,2212,9454,2293 A driven anchor device for assoaiation with formed holes in a support surface and which includes a plurality of spaced, sharp crested annular rings along [56] References Cited the shank of the device. The plurality of rings includ- UNITED STATES PATENTS ing alternating large and small diameter rings. 2,126,585 8/l938 Stone 85/21 2,650,032 11/1953 Godfrey 85/23 4 Clams 4 Drawmg Flglres ANCHOR DEVICE BACKGROUND OF THE INVENTION This invention is directed to an anchoring device for securing one workpiece to a support surface which has been provided with a hole and into which the device is driven and retained.

It is common practice to form a hole in a support surface, such as concrete, with a drill and to reuse the drill frequently without sharpening or sizing to insure that the holes formed are consistent. This practice is utilized for the formationof holes in the support surface into which an anchoring device is inserted to retain a workpiece to the support surface. This, of course, results in a wide range of actual hole sizes and, accordingly, makes conventional drive fastener anchors, such as that depicted in Rosenberg, U.S. Pat. No. l,978,329, very difficult to reliably perform. Other methods of anchoring objects to a support surface include the use of a wedge anchor such as that typified by the Lerich, U.S. Pat. No. 3,427,919, and the McCulloch, U.S. Pat. No. 3,277,770. These typical wedge anchors incorporate a plurality ofpieces and are generally expensive to manufacture and inefficient to handle in bulk shipments. They also suffer from the same limitations of reliably anchoring as a result of the wide tolerance of holes as stated above.

SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to provide a drive anchor which has high resistance to pull out in a range of actual hole sizes.

It is a further object of the invention to provide an easily installed driven fastening device which includes a plurality of independently flexing anchoring barbs while insuring that the anchoring device is properly centered to eliminate possibilities of drift of the device within the preformed hole.

These and other objects and advantages are achieved in accordance with the present invention by providing a plurality of sharp crested annular rings on the shank of a headed fastener. The adjacent annular rings are spaced from one another at their roots and are also of alternating larger and smaller diameters. The larger diameter rings being designed to be slightly larger than the diameter of the hole so that they are individually flexed, creating a plurality of sharp anchoring elements which resist retraction of the device from the hole. The plurality of smaller rings serve to insure that the device is properly centered and also serve in a function similar to the large rings when the hole is so small as to deflect the large rings beyond their anchoring capability.

The foregoing objects, features and advantages will become apparent from the following more particular description of the invention as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of a fastener embodying the principles of this invention.

FIG. 2 is an elevational view in partial section showing the application of the anchor device embodying the principles of the present invention as it is associated with a support surface.

FIG. 3 is a view similar to FIG. 2 showing the anchoring device as it is associated with a support surface having a somewhat smaller preformed hole.

FIG. 4 is an enlarged fragmentary sectional view of the anchoring device of the present invention showing the novel configuration of the rings on the shank of the device.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more specifically to the drawings wherein like parts are designated by the same numerals throughout the various figures, a fastening device 10 incorporating features of the present invention comprises an elongated shank 14 having a head section 12 integral with one end thereof. The shank is provided with a plurality of annular rings. The plurality of rings includes a plurality of relatively large diameter rings 16 alternatingly positioned along the shank with relatively smaller diameter rings 18 spaced apart at their roots by axially spacing 20.

The anchor 10 is shown in FIGS. 2 and 3 after it has been driven and exemplifies the novel features of the invention. A supporting surface 22, such as concrete, is provided with a bore 24 of a nominal size consistent with the nominal size of the anchor 10.

A workpiece 26, such as furring strips, shelving or other fixtures, is provided with a clearance hole 28 and this workpiece is placed in aligned association with the bore 24 in the support surface to allow the anchor 10 to be driven therein. As the anchor is driven by a hammer-like tool, the larger diameter rings 16 will flex or deflect upwardly and provide a biting, aggresive impingement with the wall of the bore to lock the fastener within the bore.

In a support surface, such as concrete, the bore 24 may not have a uniform structural consistency due to the presence of aggregate on one side of the bore and not on the other. In such instances the smaller annular rings I8 serve to prevent the anchor from drifting or being forced totally to one side of the hole. This drifting could obviously result in lack of biting contact on at least a portion of the periphery of the hole.

Turning to FIG. 3, the invention is shown in use and anchored within a bore 24a which is somewhat smaller than the bore 24. Such a discrepancy is not uncommon since large tolerances in actual hole sizes are produced by use of drills for a long period of time prior to disposal or resizing. In such a situation, the same nominal size anchor as used in the hole depicted in FIG. 2 may be used in a hole as depicted in FIG. 3. Attention is directed to the configuration that the large diameter annular rings assume when driven into such a hole. Because the rings 16 are sharp crested and are of a relatively thin configuration to assure flexibility, they tend to bend completely back substantially parallel to the wall of the hole and will not cut or bite into the wall. In this instance, the smaller annular rings will serve as the primary anchoring contact between the anchoring device and the wall. To assure that this effect is obtained, however, the anchoring device is designed to prevent the rings 16 from obstructing the anchoring ability of the smaller rings 18.

This is accomplished by the invention due to the particular configuration of the rings and their dimensional relationship with one another. As best illustrated in FIG. 4, the larger rings 16 are shown to preferably be formed with an approximately 30 included angle while the smaller diameter rings 18 are preferably formed with an included angle of the 40 to 60 range. The

smaller included angle of the rings 16 provides the flexibility required to perform as individual anchoring elements shown in FIG. 2. The somewhat larger included angle of rings 18 serve to provide it with adequate structure to act as a centering or locating means and yet allows these rings to function as somewhat flexible independent anchoring elements in a manner similar to the primary function of large rings 16. The anchoring ability of the smaller rings is probably shown most clearly in FIG. 3.

Since the rings 16 are of a rather thin structure they will tend to be flexed without being overstressed and possibly fracturing. However, this capability may result in flexure to the point of minimizing or reducing the anchoring capability of each individual ring. This tendency is shown in FIG. 3 where the hole is somewhat smaller than the hole in FIG. 2. The particular dimensional relationship between the crests of adjacent rings permits such a flexing by the ring 16 and yet precludes the total flexing of this ring from harming the anchoring capability of the lower ring. It is to be noted that the pitch distance P is greater than the difference between the height h of the larger ring 16 and the height I1 of the smaller ring 18. This insures that the tip of the larger ring 16 will not rest on the tip of the smaller ring 18 when it is completely flexed as in FIG. 3.

As the anchoring device is driven into a workpiece. such as concrete, the larger diameter ring 16 will scrape the sides of the hole and create loose particles of aggregate, sand, etc. These particles will aid in the locking capabilities of the device since they will tend to be lodged in the axially spaced portion 20 between the roots of the adjacent rings. This allows the anchoring members, in the form of the sharp crests of the rings, to aggresively impinge the more solid surface of the hole since the axial space 20 provides the area into which the loosened material may flow.

While the invention has been described with reference to a preferred embodiment, it will be understood that it is not intended to limit the invention to that em bodiment or to the particular embodiment described. On the contrary it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A drive-in anchor device including a shank and an integral head, the shank being provided throughout the major portion of its length with a plurality of sharp crested annular rings. said plurality including a plurality of rings having a first crest diameter and a plurality of rings having a second crest diameter alternately positioned along the length of the shank, the root portion of adjacent rings being spaced axially from one another to such an extent that the axial distance between adjacent crests is large enough to permit the larger rings to flex without interference from the smaller rings, the included flank angle of the larger annular rings being generally 30 and the included flank angle of the smaller annular rings geing generally 40-60 wherein each ring is capable of flexing and aggressively impinging an associated hole to insure securement of the anchor in a range of actual hole sizes and still allow the smaller rings to center the device within the hole.

2. A drive-in anchor device in accordance with claim 1, wherein the pitch distance between the crests of adjacent rings is at least equal to one-half the difference between the crest diameters of the larger and smaller rings.

3. A drive-in anchor device in accordance with claim 1, wherein the pitch distance between the crests of adjacent rings is at least equal to a distance ofone-half the height of the crest of the smaller ring plus the difference between the crest heights of the larger ring and the smaller ring.

4. An anchor device in accordance with claim 1, wherein the rings extend in parallel planes, which planes are generally perpendicular to the axis of the fastener. 

1. A drive-in anchor device including a shank and an integral head, the shank being provided throughout the major portion of its length with a plurality of sharp crested annular rings, said plurality including a plurality of rings having a first crest diameter and a plurality of rings having a second crest diameter alternately positioned along the length of the shank, the root portion of adjacent rings being spaced axially from one another to such an extent that the axial distance between adjacent crests is large enough to permit the larger rings to flex without interference from the smaller rings, the included flank angle of the larger annular rings being generally 30* and the included flank angle of the smaller annular rings geing generally 40*-60* wherein each ring is capable of flexing and aggressively impinging an associated hole to insure securement of the anchor in a range of actual hole sizes and still allow the smaller rings to center the device within the hole.
 2. A drive-in anchor device in accordance with claim 1, wherein the pitch distance between the crests of adjacent rings is at least equal to one-half the difference between the crest diameters of the larger and smaller rings.
 3. A drive-in anchor device in accordance with claim 1, wherein the pitch distance between the crests of adjacent rings is at least equal to a distance of one-half the height of the crest of the smaller ring plus the difference between the crest heights of the larger ring and the smaller ring.
 4. An anchor device in accordance with claim 1, wherein the rings extend in parallel planes, which planes are generally perpendicular to the axis of the fastener. 